A HELPING-ROBOT-HAND TO HARVEST VEGETABLES

The simple cucumber may be delicious on a sandwich or even in a salad, but getting it to the table is a labour-intensive and increasingly expensive job, right to the point where countries like Germany are in danger of seeing domestic cultivation move abroad.

The Fraunhofer Institute for Production Systems and Design Technology (IPK) has decided to design a simple, lightweight and intelligent two-armed robot to through in a helping hand in the harvesting of the vegetable.

These fields are huge and harvesting the ripe veggies require a small army of seasonal workers, who lie on their stomachs on the "cucumber flyers" - which can be seen below. It is a harvesting vehicle with long, wing-like attachments to carry the cucumber-pickers.

It is hard labour and it is also increasingly expensive in countries like Germany, where rising wages are making it difficult for cucumber farmers to compete with international markets. To prevent cucumber production from relocating to areas like India and Eastern Europe, Fraunhofer is working in conjunction with German and Spanish researchers on the Cucumber Gathering Green Field Experiments (CATCH) project to create a robot that can take over the job of harvesting cucumbers and similar agricultural tasks.

The CATCH team is developing a dual-arm robotic system made from inexpensive lightweight modules that are designed to be dependable and productive. Ideally, the robot should be able to identify ripe cucumbers and use its gripper arms that have five degrees of freedom to pick them and store them with a minimum of damage to the vegetable or the plant.

The dual-arm system will make use of software developed for the humanoid industrial Workbot I robot but modified to help it in cucumber harvesting, such as giving it the judgement to monitor picking operations and deal with exceptions.

"The robot can, for example, push leaves to the side using symmetrical or asymmetrical movements, or congruent and incongruent movements," says Dr Dragoljub Surdilovic, a scientist at Fraunhofer IPK. "As a result, it can automatically change directions on the fly to approach and then grasp a cucumber."

With the functionality now proven, the team hopes to produce a more advanced robot that could be commercially viable.